Distribution of particulate material

ABSTRACT

An improved particulate material handling and application system for use in combination with an aircraft including a material hopper carried by the fuselage, ducts for distributing the material extending longitudinally of the airfoils and positive displacement transfer mechanism for delivering the particulate material from the hopper to the distribution duct system. Means are provided for removing remnant or excess particulate material from the outboard ends of the distribution ducts.

United States Patent [72] Inventor Archibald B. Sellards 6928 E.Coronado Road, Scottsdale, Ariz. 85257 [21] Appl. No. 786,812 [22] FiledDec. 9, 1968 [45] Patented Feb. 2, 1971 [54] DISTRIBUTION OF PARTICULATEMATERIAL 2 Claims, 12 Drawing Figs.

[52] US. Cl 244/136, 239/171 [51] int. Cl B64d 1/16 [50] Field of Search244/136; 239/171; 169/2; 222/193 [56] References Cited UNITED STATESPATENTS 2,052,626 9/1936 Houghton, Jr 244/136(X) 3,310,205 3/1967 Meyer3,381,922 5/1968 Laing Primary ExaminerGeorge E. A. Halvosa AssistantExaminerJames E. Pittenger AttorneyDrummond, Cahill & PhillipsPATENTEDFEB 2mm 3.559.930

SHEET 1 OF 4 IYNVENTOR. ARCHIBALD B SELLARDS ATTORNEYS PATENTEUFEB 21% I3.559.930

SHEET 2 UF 4 INVENTOR.

ARCHIBAL'D :B. SELLARDS MiQZJQ ATTORNEYS PATENIEDFEB 219?: 3559.930

SHEET 3 UF 4 INVENTOR ARCHIBALD B. SELLARDS ATTORNIEYS PATENTED FEB 2mm31559330 SHEET u m 4 INVENTOR.

ARCHIBALD B. SELLARDS 1: 55- 12 BY ATTORNEYS DISTRIBUTION OF PARTICULATEMATERIAL The present invention is concerned with the distribution ofparticulate materials of various types by means of aircraft, and to astructure embodying an aircraft utilizable for such distribution.

Many types of particulate materials are distributed from the air, andthe problems attendant upon such distribution are manifold. Types ofmaterials distributed from the air include various kinds of insecticidesabsorbed on a carrier such as of diatomaceous earth, and the carriermixed with a diluent such as powdered or very finely divided clay. Theapplication of such materials is usually referred to as dusting, and thecommon practice is to utilize a relatively small plane in which a gas,usually air, is delivered under pressure through a venturi tube, and thedust entrained in such gas at the venturi tube to deliver an aspiratedcloud of dust at the rear of the plane as it moves over and along rowsof growing crops or the like. Among the problems associated with thisparticular method is that the area covered is usually small, andrepeated passes over a field are necessary with attendant problems, allof which are known to those skilled in the art. Another problem when aninsecticidal dust is applied in this manner is concerned with drifting,as a result of which the applied dust, or the lighter fractions of it,will tend to become suspended in the air and move with the wind toadjacent fields where the application is not desired, and where even theapplication may be harmful. Sometimes weed killers and defoliatingsubstances are also applied in this manner, and the results may be verycostly because of damage caused in adjacent fields. Moreover, to avoiddrifting, it is almost always necessary to fly very low, and thiscontributes to the problems of safety as well as the problems ofapplication to a wide area. It is a common practice also to applyinsecticides, seed, or even fertilizers to vast areas of forest land oropen range land to encourage growth of feed plants for animals. Inwestern grazing lands where rainfall is below average, semicommercialand experimental seedings are continuously applied to improve thegrazing land available. As part of such programs, it is not uncommon toexperiment with chemicals designed to kill off the existing vegetation,particularly vegetation representing nonindigenous transplants whichhave gotten out of hand. In any case, there has long been need for afully satisfactory method of and equipment for applying dust and otherparticulate materials over vast areas and in such a way as to avoidproblems heretofore encountered.

Various systems have been proposed for distributing dust or otherparticulate materials from aircraft. However, such systems have not beenentirely satisfactory as the capacity of the distribution system wasdependent upon the airspeed of the aircraft. For example, such systemshave been powered by auxiliary propellers, the speed of which isdependent upon the airspeed of the aircraft, or by means of venturi orother entraining apparatus which, again, are dependent upon the airspeedof the aircraft for operation and control of distribution rate.

Accordingly, it would be highly advantageous to provide a system foraerial distribution of particulate material which is not dependent uponexternal means such as auxiliary propellers, venturi or other entrainingdevices to discharge and regulate the quantity of material beingdistributed.

Also, prior art devices in which the particulate material is carried inthe wings or in portions of the fuselage remote from the center ofgravity of the aircraft are undesirable in that the handlingcharacteristics of the aircraft are changed during flight as the load ofparticulate material is distributed. Accordingly, it would be highlydesirable to provide an aircraft particulate material distributingsystem which avoids this problem.

Finally, certain prior art distribution systems for aircraft and othervehicles commonly employ material-handling apparatus the capacity ofwhich cannot be accurately controlled as the system does not involve thepositive displacement of a given volume of the particulate material but,rather, merely employs material-handling techniques which are unsuitedto accurately meter the material transfer rate.

Accordingly, a principal object of the present invention is to provideimproved means for applying particulate material from the air.

Another object is the provision of an improved applicator of the typeidentified which may be adjusted to apply substantially any type ofparticulate material, as contrasted with devices of the prior art whichwere more specialized in their capacities.

Still another object is the provision of improved applicating means ofthe character identified which may be applied to already-existingaircraft, or which may be built into special aircraft if desired.

Yet another object of the invention is the provision of improvedapparatus for aerially applying particulate materials in which thedischarge rate of the apparatus is substantially independent of thespeed of the aircraft.

Another object of the invention is to provide a system of the typeidentified in which the discharge rate can be accurately controlled andvaried over wide ranges to allow for handling a wide variety ofparticulate materials and to enable the application of such materials atwidely varying application rates.

These and other, further and more specific objects and advantages of theinvention will become apparent from the following detailed descriptiontaken in conjunction with the drawings, wherein:

FIG. 1 is a perspective view showing an embodiment of the presentinvention as incorporated with a standard type of aircraft already inexistence which is particularly useful when the wing structure of theexisting aircraft will not accommodate internally disposed distributionapparatus;

FIG. 2 is a fragmentary enlarged perspective view showing a part of theapplicating mechanism of FIG. 1 separated from the aircraft proper;

FIG. 3 is a fragmentary view showing a hopper associated with theairplane, a special airfoil, and other parts such as will be seen bylooking along the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary plan view showing a part of the special airfoilcarrying a part of the distribution equipment, the airfoil being partlybroken away at its outer end to show details of construction andoperation;

FIG. 5 is a similar plan view, but showing the center portion of thespecial airfoil, and a part of the hopper for the com minuted materialbroken away, with its bottom in plan view;

FIG. 6 is a fragmentary sectional view taken along the line 6-6 of FIG.5;

FIG. 7 is a fragmentary sectional view looking along the line 77 of FIG.5;

FIG. 8 is a perspective view of an aircraft incorporating another andpresently preferred embodiment of the invention in which the liftingairfoil structure of the aircraft is utilized as the support for majorportions of the distribution apparatus;

FIG. 9 is a perspective view of the distribution apparatus employed inthe aircraft of FIG. 8;

FIG. 10 is a cutaway sectional view of a portion of the distributionduct of the apparatus of FIG. 9; and

FIGS. 11 and 12 are, respectively, elevation and plan views of theaircraft of FIG. 8 showing the location of the assembly of FIG. 9 withinthe existing aircraft structure which is indicated by dashed lines.

Briefly, in order to achieve the objects and advantages of my invention,I provide an apparatus for aerially applying particulate materials whichis used in combination with an aircraft having a load-carrying fuselageand laterally extending airfoils. The improved material-handling systemincludes a hopper for particulate material which is carried by thefuselage, distribution ducts which extend longitudinally of the airfoilsand each of which has a plurality of distribution openings. A transferduct connects the hopper with each of the distribution ducts andpositive displacement delivery means for the particulate material,having a capacity independent of the air speed of the aircraft, areoperatively disposed within the transfer and distribution ducts. Meansare provided at the outboard ends of the distribution ducts for removingremnant particulate material which is not discharged through thedistribution openings as the particulate material is passed through thedistribution ducts. In a preferred embodiment of the invention, thestorage hopper carried by the fuselage is located substantially at thecenter of gravity of the aircraft to avoid gross changes in aircrafthandling characteristics as the load is progressively discharged. Inthis embodiment, the distribution ducts extend longitudinally within thelifting airfoils of the aircraft and the particulate material is movedthrough the transfer duct into the distribution ducts by means ofvariable capacity positive displacement augers operating within theducts. The particulate material carried by the augers which is notdischarged through the distribution openings is discharged through theopen end of the distribution duct. This open end is swept clean ofremnant particulate material by air forced into the end of thedistribution ducts by means of a petot tube positioned proximate theends of the ducts.

In another embodiment of the invention, the distribution ducts areshaped in the form of an airfoil which is suspended beneath the liftingairfoil of the aircraft, and means are provided for returning the excessparticulate material from the outboard end of the distribution airfoilto the hopper.

Referring now to the drawings, the last-mentioned embodiment of theinvention is depicted in FIGS. l7 in which a conventional type ofairplane, indicated generally by the reference character 10, may bemodified to transport and distribute a relatively very large amount ofparticulate material over a very large area, it being understood, ofcourse, that the particular type and size of airplane and distributioncapacity being determined in part at least by conditions encountered. Inthe present instance, the airplane used is a multiengine type with afuselage 11 and wings 12, the engines being supported in nacelles in thetwo wings. As shown, the airplane is of the midwing type, but it shouldbe understood that any conventional design of airplane can, as a rule,be used with substantially equal facility.

Particulate material is distributed from a pair of distribution airfoils13 suspended from and secured to the wings 12 by a series of struts 14.Since the present invention is not concerned with the airplane as suchnor the specific manner of supporting and suspending the distributingairfoils 13, details of construction are not provided.

The distribution airfoils 13 are, in effect, mirror images of each otherand for convenience will be described as if they are identical exceptinsofar as the text indicates a different relationship. The distributionairfoils 13 are preferably substantially neutral aerodynamically; thatis to say, they provide neither lift nor control of the airplane and aredesigned to produce a minimum of drag, so that for all practicalpurposes, when the airplane is in level flight, the distributionairfoils will not influence the movement of the aircraft in anysubstantial wav.

As FIGS. 4 through 7 particularly show, the distribution airfoils 13 arehollow and each has an entering edge 16 and a trailing edge 17. Spacedfrom the trailing edge 17 is a baffle 18 running longitudinally of eachairfoil, but each baffle communicating with and being integral with anarcuate portion 19, the two arcuate portions 19 being in back-to-backrelation and defining the center point between the two distributionairfoils 13. A hopper 21 has its bottom surface approximatelycoextensive with the top surface of the airfoils 13 as will beexplained, such hopper extending upwardly through the bottom portion ofthe fuselage and being so constructed and arranged at the top that theparticulate material to be distributed may be introduced into the hopperfrom inside the fuselage of the airplane. This construction may beconventional in any desired manner, but preferably the arrangement issuch that packages, suitably bagged, of the particulate material may becarried as cargo in the fuselage, and introduced as required into thehopper while the airplane is in flight.

To distribute the particulate material, it is delivered from the hopperin an amount somewhat greater than will pass through openings providedin the bottom portion of the airfoils 13, moved longitudinally of thefoils for distribution, the

residue returned back to the center portion of the airplane. and suchresidue returned to the hopper and/or to the distribution mechanism forfurther delivery as required. A very satisfactory method ofaccomplishing this result is shown in the drawings. Each foil has aplurality of aligned openings 22. and a longitudinal plate 23 above suchopenings 22 provided with similar openings 24 is adjustable with respectto the foil so that the full opening 22 of the line of openings isavailable for the passage of the particulate material, or the effectivesize of the opening may be reduced by overlapping the openings 22 and 24slightly as shown in FIG. 5, or finally, the openings 22 may be entirelyclosed by complete actuation of the longitudinal plate 23, if desired.Each of the longitudinal plates 23 is adjustable by means of a pistonrod 26 actuated by a piston 27 within a hydraulic cylinder 28, to becontrolled by a hydraulic fluid delivered through lines 29 and 31. Anysuitable means for providing hydraulic fluid under pressure, such as anyof the conventional hydraulic pumps, may be utilized, or for that matterthe usual hydraulic system of the airplane may be utilized if desired.The invention is concerned only with the provision of suitable means,preferably hydraulic, for controlling the position of the longitudinalplate 23 and thereby the area of the openings through which theparticulate material passes.

The particulate material is delivered by means which will be describedto a position where it will be moved along across the face of theopening 22 by a series of paddles 32 carried by a belt 33 containingopenings for receiving projections 34 from special sprocket wheels 36and 37. Sprocket wheel 37 is carried on an idler shaft 38 but sprocketwheel 36 is carried on a shaft 39 driven by a hydraulic motor 41 carriedon brackets 42, the hydraulic motor 41 being supplied with hydraulicfluid from a tube 43, and the spent fluid being returned through a tube44 (see FIG. 6).

The hopper, indicated generally by the reference character 21, has sides46 and 47, a front 48 and a back 49, at least the lower part of saidsides, front and back sloping inwardly to a bottom 51 with a pair ofopenings 52, only one of which appears in FIGS. 5 and 6. The junctionbetween the rounded portions 19 of the baffle 18 is the separation pointbetween the two foils 13, and it should be recalled that the hopperextends over the entrance point for the particulate material on bothfoils as FIG. 1 clearly shows. Above the bottom 51 of the hopper andabove the opening 52 is a closure plate 53'which also has two openings54 (one being shown in the drawing) adapted to match with the twoopenings 52. The bottom 51 and the two openings 52 and 54 are slightlyabove the distribution airfoils 13, and a short section of pipe 56delivers the particulate material from the hopper through an opening 57in the top surface of the airfoil for delivery to an area indicated bythe letter A in FIG. 5, which area is, of course, directly under the twoopenings 52 and 54. The plate 53 has a bracket 61 to which the end of apiston rod 67 is rotatably secured, the piston rod being controlled by asuitable piston (not shown) within a control cylinder 68 mounted on abracket 69 as shown particularly in FIG. 3. The position of the parts inFIG. 3 corresponds to the position of the parts in FIGS. 5 and 6 wherethe particulate material in the hopper can drop continuously down to twopositions corresponding to the point A in the two airfoils 13.

It should of course be understood that while the openings 52 and 54 willnormally be aligned, they may be only partially aligned, so that thematerial dropped into the airfoils for distribution will be reduced.Normally, this is not necessary, because in the design of the equipment,enough particulate material is delivered to the airfoil so that even asit is moved longitudinally of the airfoils over each of the openings 22,there will always be more material than will fall through the openings,and the remainder or excess material will then be brought back to anopening 71 which is approximately directly opposite the openings 52 and54 as seen in FIG. 6. The material dropping through openings 71 enters acurved delivery chute 72, suitably of circular cross section,communicating with the bottom of an upright return tube 73 (FIGS. 2, 3.5 and 6) containing an elevator screw 74 in the form of an augersupported on shaft 76 and driven by a hydraulic motor 77, whichhydraulic motor may be up within the body of the airplane. Forstability, a bottom end 76' ofthe drive shaft 76 may engage a bearingsurface in the bottom of the upright 73 to stabilize the position of theelevator screw 74 centrally of the upright 73. Thus, even though thehopper 21 may be substantially filled with particulate material. theauger will deliver excess material back into the body of the material inthe hopper for redelivery back to the delivery airfoils 13.

Reference has already been made to the rounded portion 19 of the baffle18. A similar curved portion 78 is provided near the outer end of eachairfoil 13. so that as the particulate material is moved outwardly ofthe airfoil between the baffle 18 and the belt 33, it will be caused toturn backwardly on itself by the action of the paddles 32 and movebetween a contiguous portion of the belt 33 and the inner surface of theforward edge 16 of the foil 13. Looking at FIG. 6, it will be seen thatthe space available on both sides of the belt is approximately equal,and a relatively large amount of material to be sprayed can be movedcontinuously across the openings 22, and the excess returned to thehopper 21 as the airplane is in flight.

I have already pointed out that preferably airfoil 13 is shaped so as tohave a minimum of drag and substantially no aerodynamic effect on theforward movement of the aircraft when it is in level flight. It will benoted, however, particularly by reference to FIG. 7, that the openings22 are slightly behind the position of maximum thickness of the foil 13,so that there is a very slight rarefaction at the location of theopenings 22, and the particulate material will be free to drop throughthe openings 22 assisted slightly by partial negative pressure, andbeing spread into individual particles as they enter the slipstream atthe rear of the airfoil. To facilitate this action, however, without atthe same creating the necessity of providing a special type of foil 13which could have an undesirable effect on flight action at variousattitudes of the plane, a plurality of special strip foils 81 aresecured to the bottom of the distribution foils 13 just in advance ofeach of the openings 22, and confined in longitudinal dimension to thearea occupied by such openings. These special strip foils 81 aredesigned to increase the negative pressure at the openings 22, andfacilitate delivery of particulate material through such openings. Itshould be borne in mind that many types of materials, all of which arein the form of discrete particles such, for example, as seeds, willrelatively simply fall through an opening such as 22 without thepossibility of being packed up by partial compression such as can occurwhen hygroscopic materials or materials capable of becoming packed orcaked, such as, without limiting the generality, sulfur, are beingapplied. In those instances, however, where there is any tendencywhatsoever for the particulate material to ball up or pack, the stripfoils 81 assure that there will be continuous delivery because of thenegative pressure, or partial vacuum, created at these points.

For convenience of illustration, many of the parts utilized in thepresent invention are shown in the open without streamlining and withoutany marked attempt to cause the parts to contribute to the aerodynamicstability of the aircraft. While an aircraft installation exactly suchas shown may be utilized with good results, to a considerable extent theparts are probably at least partially streamlined, and some of the partswhich are shown out of the cabin may, in fact, be housed within thecabin of the aircraft. Furthermore, the aircraft shown is generally ofthe B17 configuration, without a showing of the retractable landinggear, but those skilled in the art will understand that other types ofaircraft can be used, and that in modifying the airplane to include thefeatures of the present invention, all of the usual parts of theairplane, including the retractable landing gears, should still operatein the conventional manner. It may be noted, however, that there arecertain advantages in using a midwing airplane, or for that matter,

even a high-wing airplane, because such aircraft construction definitelytakes the airfoil away from too close proximity of ground level, andspaces far enough from the airfoil as to avoid any possible aerodynamicinterference with the airfoil function.

The manner of using the aircraft assembly of the present inventionshould be apparent from the above description. Briefly, the hopper 21will normally be filled with the material to be sprayed or distributedon the ground or into contact with vegetation, the plate 53 beingadjusted to close the openings 52. Usually, the carrying capacity of theplane will be greatly in excess of that which will be stored in thehopper 21, and any suitable means may be employed for supportingadditional material in the fuselage but outside the hopper. One methodalready mentioned is to carry the material to be distributed in the formof relatively large paper bags to be dumped manually into the hopper asit becomes partly emptied, or if desired, any of the usual availableconveyor systems may be employed to transfer the sprayed material fromstorage hoppers to delivery hoppers. The present invention is notconcerned with these types of operations, but makes available to theoperator of the spray equipment the ability to carry very large amountsof the material to be sprayed so that spraying of very large fields oropen areas is possible in one operation without returning to the ground.This is to be contrasted with conventional spray equipment in which asingle hopper is filled on the ground, and the airplane must be returnedto a small field for refilling whenever the hopper has become emptied.The present invention also avoids another very serious problem such asoccurs in spraying certain types of material, in that the material maynot feed uniformly from the hopper and will shift the center of weightof the airplane so badly as to sometimes cause serious accidents. In thepresent case, an assistant or assistants who may be copilots areavailable to inspect and supervise the movement of the material beingsprayed continuously so that during the entire flight of the plane, onceit has reached its operating destination, will be devoted to thespraying operation. Since delivery is made over a very wide path in avery uniform manner, the results obtained are unusually successful.

It is of course obvious that once the airplane is brought to theposition where distribution is to be started, the hydraulic motor 68will be activated, opening the hopper in two places at the bottom fordelivery of the comminuted material to be sprayed to the two points A atthe inner end of the two airfoils 13. At the same time, the motors 41and 77 will be started to deliver the particulate material entirelyacross both foils 13 for delivery through the openings 22, and if thesize of the openings 22 has not been properly set, then the hydraulicmotor 28 will be actuated to move the strip 23 in either direction tocontrol the openings 22 and deliver exactly the right amount of materialas the airplane moves along. Excess material which does not fall throughthe openings 22 is, of course, eventually brought to the opening 71, anddropped down into contact with the elevator screws 74 for delivery backto the hopper 21.

The presently preferred embodiment of the invention is depicted in FIGS.8-12, in which like reference numerals indicate the same elements. Inthis embodiment, the distribution ducts 91 have a plurality ofdistribution openings 92 therein. The distribution openings 92 extendthrough the leading edge 93 of the wing of the aircraft 94. Theparticulate material is stored and transported to the distribution sitein a hopper 95 located at substantially the center of gravity of theaircraft 94. The particulate material is transported from the bottom ofthe hopper 95 through the transfer ducts 96 and 96a. The particulatematerial is moved through the duct system by means of a positivedisplacement auger 97 operating within the ducts. The augers within thetransfer ducts 96 are powered by an electric or hydraulic motor 98coupled to pulleys 99 affixed to the ends of the augers by means ofabelt drive 100. The augers within the transfer ducts 96a anddistribution ducts 91 are powered by electric or hydraulic motors 101,the augers being coupled at the joint between the transfer duct 96a andthe distribution duct 91 by means of a flexible connector 102 which canbe of the familiar universal joint" type or can be constructed of rubberor other elastomeric material in the manner of the familiar metalastic"coupling. Excess particulate material which has not been discharged fromthe distribution ducts 91 is removed from the duct system by expellingthe material through the open end 91a of the duct 91. To facilitate theremoval of this excess material, a pitot tube 103 is provided which,because of the ram effect, forces air outwardly through the open end 91aof the distribution duct 91. An airfoil 104 encompasses a sufficientportion of the distribution duct 91 extending beyond the wing tip toensure no adverse effect on the flight characteristics of the aircraft.

Since the particulate material is removed from the hopper 95 andtransferred through the duct system to the distribution openings 92 bymeans of a positive displacement auger 97, and since the speed ofrotation of the augers may be accurately controlled by adjusting thespeed of the drive motors 98 and 101, it is possible to very accuratelycontrol the rate of distribution of the particulate material and thisdistribution rate can be maintained without depending on maintaining aconstant airspeed, since no part of the system is powered by propellers,venturis or other contrivances which are dependent on the airspeed ofthe aircraft to regulate their capacity. Similarly, in the embodiment ofFIGS. 1-7, the speed of the positive displacement pedal conveyor can beaccurately controlled by adjusting the rotational speed of the motor 41,and additional control of the distribution rate, independent of thespeed of the aircraft, is provided by means of the slide 23 to adjustthe size of the distribution openings 22.

A relatively simplified functional embodiment of the invention has beenshown and described in detail so that those skilled in the art mayunderstand the manner of practicing the invention.

Iclaim:

1. Apparatus for aerially applying particulate materials to the earth,comprising, in combination:

a. an aircraft having a load-carrying fuselage;

b. a particulate material hopper carried by said fuselage;

c. distribution ducts extending laterally of said fuselage and having aplurality of distribution openings therein;

d. transfer duct means connecting said hopper and said distributionducts;

e. positive displacement particulate material delivery means having acapacity independent of the airspeed of said aircraft operativelydisposed within said transfer duct means and distribution ducts;

f. rate-of-distribution means for selectively-controlling the rate atwhich particulate materials pass-through said material delivery means;and

g. ejection means for removing from the outboard ends of saiddistribution ducts remnant particulate material which is not dischargedthrough said distribution openings, each of said ejection meansincluding a pitot tube communicating with one of said distribution ductsoutboard of said plurality of distribution openings for urging remnantparticulate material outwardly for ejection, each of said ejection meansfurther including an airfoil encompassing a sufficient length of theoutboard end of one of said distribution ducts to mitigate adverseeffects on the flight characteristics of said aircraft.

2. Apparatus for aerially applying particulate materials to the earthcomprising, in combination:

a. a fixed-wing aircraft having a load-carrying fuselage. and

laterally extending lifting airfoils;

b. a particulate material storage hopper carried by said fuselage andlocated substantially at the center of gravity of said aircraft;

c. distribution ducts extending longitudinally of said lifting airfoilsand having a plurality of distribution openings therein;

d. transfer duct means connecting said hopper and said dis tributionducts;

e. positive displacement particulate material delivery auge'rs having acapacity independent of the airspeed of said aircraft operativelydisposed within said transfer duct means and distribution ducts;

f. rate-of-distribution means for selectively controlling the rate atwhich particulate materials pass through said material delivery auger's;and

g. ejection means for removing from the outboard ends of saiddistribution ducts remnant particulate material which is not dischargedthrough said distribution openings, each of said ejection meansextending beyond the wing tip of said aircraft and including a pitottube communicating with one of said distribution ducts outboard of saidplurality of distribution openings for urging remnant particulatematerial outwardly for ejection, each of said ejection means furtherincluding an airfoil encompassing a sufficient length of the outboardend of one of said distribution ducts to mitigate adverse effects on theflight characteristics of said aircraft.

1. Apparatus for aerially applying particulate materials to the earth,comprising, in combination: a. an aircraft having a load-carryingfuselage; b. a particulate material hopper carried by said fuselage; c.distribution ducts extending laterally of said fuselage and having aplurality of distribution openings therein; d. transfer duct meansconnecting said hopper and said distribution ducts; e. positivedisplacement particulate material delivery means having a capacityindependent of the airspeed of said aircraft operatively disposed withinsaid transfer duct means and distribution ducts; f. rate-of-distributionmeans for selectively controlling the rate at which particulatematerials pass through said material delivery means; and g. ejectionmeans for removing from the outboard ends of said distribution ductsremnant particulate material which is not discharged through saiddistribution openings, each of said ejection means including a pitottube communicating with one of said distribution ducts outboard of saidplurality of distribution openings for urging remnant particulatematerial outwardly for ejection, each of said ejection means furtherincluding an airfoil encompassing a sufficient length of the outboardend of one of said distribution ducts to mitigate adverse effects on theflight characteristics of said aircraft.
 2. Apparatus for aeriallyapplying particulate materials to the earth comprising, in combination:a. a fixed-wing aircraft having a load-carrying fuselage, and laterallyextending lifting airfoils; b. a particulate material storage hoppercarried by said fuselage and located substantially at the center ofgravity of said aircraft; c. distribution ducts extending longitudinallyof said lifting airfoils and having a plurality of distribution openingstherein; d. transfer duct means connecting said hopper and saiddistribution ducts; e. positive displacement particulate materialdelivery augers having a capacity independent of the airspeed of saidaircraft operatively disposed within said transfer duct means anddistribution ducts; f. rate-of-distribution means for selectivelycontrolling the rate at which particulate materials pass through saidmaterial delivery augers; and g. ejection means for removing from theoutboard ends of said distribution ducts remnant particulate materialwhich is not discharged through said distribution openings, each of saidejection means extending beyond the wing tip of said aircraft andincluding a pitot tube communicating with one of said distribution ductsoutboard of said plurality of distribution openings for urging remnantparticulate material outwardly for ejection, each of said ejection meansfurther including an airfoil encompassing a sufficient length of theoutboard end of one of said distribution ducts to mitigate adverseeffects on the flight characteristics of said aircraft.